1. Technical Field
The disclosure relates to light emitting diodes, and particularly to an LED unit.
2. Description of the Related Art
Light emitting diodes (LEDs) have many advantages, such as high luminosity, low operational voltage, low power consumption, compatibility with integrated circuits, easy driving, long term reliability, and environmental friendliness. These advantages have promoted a wide use of the LEDs as a light source. Now, the light emitting diodes are commonly applied in environmental lighting.
Light from a common LED transfers to the specific wavelength by a fluorescent layer. However, an encapsulation of the LED is fixed on the substrate. The optical characteristics of the common LED cannot be adjusted, according to the specific needs.
Therefore, it is desirable to provide an LED unit which can overcome the described limitations.